Curing Behavior And Preparation Of Water-Based Emulsion Of Epoxy Resin

As epoxy resin possesses good mechanical strength,excellent adhesivity,thermal and chemical stabilities,it has been widely used in coating,adhesive and composite fields.However,epoxy resin with high initial viscosity is difficult to control the curing rate,and its performance is strongly influenced by the curing formula and condition.Moreover,it scarcely contains hydrophilic groups,which is easy to phase-separate in water and difficult for the waterborne applications.These disadvantages of epoxy resin greatly limit its applications.In this study,we selected n-butyl glycidyl ether as a reactive diluent,A,B,C and D as the curing agents,Tween80 and Span80 as the emulsifiers,to study the property modification and application of epoxy resin.First,the effect of n-butyl glycidyl ether,used as a reactive diluent,on the rheological property of bisphenol A epoxy resin was investigated.We find that the addition of n-butyl glycidyl ether decreases the viscosity obviously and improves the fluidity of epoxy resin;the cured sample also has good mechanical property.Curing behaviors of diluted epoxy resin at the medium(60?)and high(140?)temperatures were further examined.It indicates that the curing rate can be regulated by varying the content of curing agent A.Infrared spectrum shows that the curing reaction of the epoxy resin proceeds effectively at the medium and high temperatures.With increasing the curing temperature and the content of curing agent A,the mechanical property of cured epoxy resin improves.When the waiting-on-cement(WOC)time is 1-2 h,the compressive strength and Young's modulus of the cured epoxy resin at medium temperature are 119 and 729 MPa,respectively;those of cured epoxy resin at high temperature are 239 and 1049 MPa,respectively.This study suggests that diluted epoxy resin curing system is successfully established,and its curing behavior and performance can be effectively controlled by changing content of curing agents.Then,we studied the performance of diluted epoxy resin curing system in practical environments.Performance of cured epoxy resin in water or kerosene is slightly distinct from that in the atmosphere,implying good performance stability in special environments.The epoxy resin system can be mixed homogeneous with quartz sand and oil well cement,showing good compatibility performance.Meanwhile,it displays good bondability to rock core and stainless steel sheet;the bonding strengths at 60 and 140? are 5.13 and 7.89 MPa,respectively.This study shows that the cured epoxy resin system in different environments possessed excellent performance,which can be used in combination with various materials.Finally,waterborne modification of diluted epoxy resin curing system and its application in sand consolidation were studied.We find that epoxy resin system can be emulsified by the Tween80/Span80 compound emulsifiers with specified hydrophilic-lipophilic balance value forming a stable and homogeneous solution with good storage stability.The curing effect of the three curing agents,including A,C,and D,was investigated in the water environment.It is found that curing agent A exhibits best mechanical property and fastest curing rate.Compressive strength and permeability of the cured sand pillars were evaluated comprehensively;the cured sand pillars were prepared through curing the epoxy resin emulsion with the three curing agents at 60?.The sand pillar cured with curing agent A shows excellent sand consolidation property,and has compressive strength and permeability of 1.82 MPa and 0.025 D,respectively.This indicates that the diluted epoxy resin curing system can be well used in the sand consolidating situations.Mechanical strength and permeability of the optimal sand consolidating system at different temperatures and water contents were studied.It shows that the performance of the sand-consolidating system remains stable at different temperatures and water contents,which can be applied in the practical sand consolidating situations.